A full task-isolation mode for the kernel

TLB shootdowns are the least of the problem. I see multi-millisecond pauses caused by the behavior in question. Such files have to live in a tmpfs, shmfs, or the like, and snapshots of the stats normally kept in them have to be produced by copying to another file in the same fs, and then out, to prevent pathological stalls.

The core that is busy writing out the page necessarily generates contention on the isolated core's cache bus, as dirty cache lines are copied out of it, but no TLB shenanigans ought to be needed.